Large cross-country transmission lines carrying clean energy from remote rural areas to population centers will be a key strategy for reducing emissions.
But as a project in Minnesota illustrates, the grid puzzle is more complicated than that.
Connecting central and northern Minnesota, the Northland Reliability Project will reinforce the state’s electric grid with new transmission lines as fossil fuel-powered plants close and utilities rely on more clean energy generation.
The Midcontinent Independent System Operator, Inc., known as MISO, chose the Northland Reliability Project as one of 18 transmission projects in a more than $10 billion first tranche budget. The 180-mile-long project has the initial group’s second-highest budget: $970 million.
Transmission has been a challenging issue nationwide as utilities and customers transition to producing and consuming more clean energy. Rich in wind power, the Midwest is no different, with MISO having seen developers pull projects because of a lack of transmission.
Allete subsidiary Minnesota Power and generation and transmission cooperative Great River Energy will build the project from central Minnesota to the mining-intensive Iron Range. The project adds double-circuit 345-kilovolt transmission lines to a route where smaller lines will still operate.
Beth Soholt, executive director of Clean Grid Alliance, said Minnesota Power and Great River Energy wanted the project to improve reliability in their territories. The project “supports and beefs up the regional grid in this particular location,” she said. Because it crosses the borders of the utilities, they will build and own it, but MISO will pay for it.
Northland’s route runs near two retiring fossil plants and Xcel Energy’s Monticello nuclear energy plant. Owned by Minnesota Power, the Boswell Energy Center in Cohasset near the northern terminus will close in phases by 2035. The other coal plant, the Xcel-owned Sherburne County Generating Station also known as Sherco, will close by 2030.
Dan Gunderson, Minnesota Power’s vice president for transmission and distribution, said the Northland project “will be a critical element to ensure we have regional stability for our large customers in the northern part of the state,” he said.
Unlike most regional utilities primarily serving commercial and residential customers, Minnesota Power’s most significant customer base consists of mines that often draw enormous amounts of electricity for operations. Gunderson said the line would be a key element in meeting demand, especially in winter when it grows significantly.
Great River Energy’s vice president and chief transmission officer, Priti Patel, explained the challenge: “When we think of this energy transition, it’s not just about bringing in transmission to serve more renewables; it’s also about the fact that generation is retiring and retirements create the need for new transmission,” she said.
When baseload generation decreases, the geographical disparity of power sources increases and voltage stability concerns grow, Patel said.
The transmission line “is not directly connecting right now to any renewable generation specifically,” she said. “But part of this energy transition is maintaining reliability. And when you have baseload plants retiring and more renewables connecting, you need transmission to maintain the stability of the system.”
At least at the southern end of the line, Northland links to a Sherco substation. Xcel will be building a 460-megawatt solar plant at its Sherco site to generate electricity for the region and the Northland will likely carry some of it to customers. Earlier this year, Xcel proposed another solar array to bring the total output to 710 megawatts.
Soholt said MISO calls the first tranche investments “least regrets” transmission lines because studies demonstrated that the projects showed the most significant promise of adding reliability and resiliency, she said. Any new transmission will only help Minnesota meet its goal of generating electricity from carbon-free sources by 2040, Soholt said.
MISO’s long-range planning document points out that lines from south to northern Minnesota are 115 kV and 230 kV, not enough capacity for Minnesota Power to comfortably serve customers with power coming from the Twin Cities.
“This large geographical disparity in generation and weak transmission causes voltage stability concerns for a majority of the Minnesota system north of the Twin Cities,” MISO wrote.
No organized opposition has emerged, but Red Wing attorney Carol Overland has misgivings. A persistent critic of transmission line projects for decades, she contends that transmission capacity will grow as coal plants shut down. “There’s a lot of the system already existing that will have opened up capacity when coal plants shut down,” Overland said.
Utilities earn more profits from building transmission than from generating and selling electricity, she said, making them proponents of large projects. Since transmission costs fall to ratepayers, utilities benefit without taking much financial risk, Overland said.
Overland suggested that generating clean energy closer to where it will be consumed would decrease the need for transmission and offer a more stable grid. For the same amount of money that will be spent on transmission, “you could get a lot of solar [installed] where it is needed,” Overland said. “But [utilities] can’t get a rate of return on that.”
Construction is scheduled to begin in 2027 with the transmission project to be complete and carrying electricity by 2030.